1. Field of the Invention:
The present invention relates to a processor for continuously cooking grains such as rice, wheat, beans, corn. More particularly, it relates to a processor for continuously cooking in a short time a large amount of grain, using a minimal amount of water, resulting in cooked grains having a good taste, which are based on a novel cooking method.
2. Description of the Prior Art:
The importance of grains such as rice, wheat, beans, corn or the like has become greater recently as it has been recognized that grains have a high nutritive value and are valuable as a diet food, so that cooking large amounts of grain has become increasingly important.
People of Southeast Asia and the Middle East, in addition to Japanese, Chinese and Koreans, have lived on grains, especially, rice as their main staple. It is well known that in the cooking of rice and/or wheat, the amount of water used and the heating method directly affect the taste of the resulting product.
According to a conventional rice-cooking process, rice is immersed in a certain amount of water so that a certain amount of water enters into each grain of the rice thereby attaining gelatinization. Although the time for absorbing this water depends upon the immersion temperature, it is generally 30 minutes at an ambient temperature. The amount of water needed ranges from 1.1 to 1.2 times by volume the amount of rice when polished rice is used, while the amount of water required for unpolished rice is equal to the volume of the rice. Then, the rice is subjected to a pre-heating step wherein the rice is gently heated in the beginning. This is because if the rice is quickly heated, gelatinization is accelerated on the surface of the rice grains alone thereby reducing the heat-transmission and the water-absorption to the core portion of the rice grain particles, resulting in a half-cooked rice. In order to obtain properly cooked rice, the water is first heated to 70.degree. C. for approximately 10 minutes. As the temperature of the water rises, the water-absorption into the rice grain particles proceeds so that micell bondings in the rice grain particles are released thereby attaining gelatinization on the outer portion of each grain. Then, the water is rapidly brought to a boil so that the starch in the core portion of each grain is gelatinized. Such boiling is continued for about 15 minutes. A certain amount of the boiling water is absorped in to the rice particles and the remainder is evaporated in to the atmosphere, while the rice is cooked by steam produced from the boiling water. Then, the heat is reduced. The lid of a rice-cooking pot must not be opened immediately. When the excessive water on the surface of each grain particle has been evaporated, the heating is stopped. Gelatinization proceeds in the core portion of each rice particle, resulting in properly cooked rice. For complete gelatinization, it generally takes 20 to 30 minutes at a temperature of 98.degree. C.
Such a conventional rice-cooking process consumes too much time (i.e., totaling to 70-90 min.) in order to obtain properly cooked. Moreover, the amount of rice which can be cooked is limited as uniform heat is required for each rice grain. Also, with conventional cooking pots, condensed drops of moisture attach to the cooked rice as the atmosphere in the pot is cooled thereby reducing the taste of the cooked rice and making it sticky. It must also be mentioned that water used for washing or immersing the rice grains causes water pollution.